LED lighting systems are used in a number of lighting applications including that of providing mood and functional lighting effects. In this regard, it is desirable for an LED lamp to be capable of adjustably rendering a broad spectrum of correlated colour temperatures, brightness and other light emission characteristics which are required to provide vivid mood and functional lighting effects.
Problems exist in seeking to cost-effectively enhance LED lamps so as to exhibit mood and functional lighting performance characteristics comparable with the above requirements, whilst at the same time providing a compact-sized module having suitable and effective thermal dissipation capability in the context of the device design. For instance, whilst the correlated colour temperature spectrum may be enhanced by seeking to increase the capacity of RGB LEDs available to effect colour mixing with white light LEDs, this also results in additional design costs and complexity, and, requires additional power and thermal dissipation capacity which may not be suitably available within the constraints of a compact-sized module design. Conversely, certain LED technologies such as the Philips Hue device are implemented in the form of a compact sized LED lamp module, however, as it utilises a relatively limited range of RGB LEDs, the resulting correlated colour temperature spectrum that can be rendered, the luminous flux and beam angle, are perceived to be relatively poor.
Existing LED lighting systems also tend to utilise a switch-on switch-off approach whereby when switching from one lighting mode to another, the LED driving current in different LED output channels are changed in an instantaneous step-change to adjust the brightness and colour settings. However, effecting instantaneous change of the colour and brightness characteristics is perceived to cause discomfort for users.